Bolt-anchor



C. S. GIRVAN.

BOLT ANCHOR.

APPLICATION min 1ULY14, 1915.

Patented Nov. 8, 1921.

UlMINIMUMHIHIIIHMMJHIIrml UNITED STATES PATENT OFFICE.

CHARLES S. GIRVAN, OF WHITE PLAINS, NEW YORK, ASSIGNOR T O LAWRENCES.

JACKSON, OF NEW YORK, N. Y.

BOLT-ANCHOR.

Application filed July 14, 1916.

cordance with the process of, and from a modified form of the blanksshown in, my application, Serial No. 868,963, tiled October 28, 1914.The expansion bolt anchor shown in the Joseph patent consists of anyintegral tubular body portion with expansion members integrallyattached to said body portion and creased longitudinally so as to form atapering interior and a substantially cylindrical exterior. Theseexpansion meml bers `are internally screw-threaded so that a suitablebolt may be screwed into them and they are thereby expanded to grip thewall.

The process of making the anchor as set forth in my application abovementioned consists in stamping a rectangular or slightly fan-shapedblank from a piece of metal having a body portion with integralexpansion members attached thereto and off-setting a portion of each ofsaid mcmbers and bending the blank upon itself, leaving an openingtherethrough, one of the blanks shown in that application being substantially the same as Figure 1 of the present application, and whichwill be described hereinafter.

The present invention relates particularly to the provision of meanswhereby thc adjoining ends of the body member may be fastened or lockedtogether and held in register with each other, and also in the provisionof means onl the body member of the anchor to bear against the walls ofthe opening into which it is placed so as to hold the ends of the bodymember in contact with each other and to prevent the anchor fromrevolving in the hole while the expanding bolt is being screwed intoposition.

It is found in devices of this character that in screwing the expandingbolt into position in the anchor, strain is placed upon the expandingmembers of the anchor which, in some instances, tends to move them fromtheir normal median position with respect to the adjacent members. Thiscauses the Specification of Letters Patent.

Patented Nov. 8, 1921.

Serial ANo. 109,209.

abutting ends of the body member to be displaced relatively to eachother, thereby decreasing the efficiency of the device by causing anirregular expansion of the members and an irregular bearing of themembers, and consequently, an irregular distribution of the pressure andgripping of the members caused by the introduction of the bolt.Furthermore, the displacement of the expansion members may be caused bycarelessness in introducing the anchor into the hole.

It is one of the purposes of this invention to so arrange the bodymember ythat the ends will be held in register with each other as wellas in contact with each other whatever stress or strain may be placedupon the eX- panding members, whereby the bad effects, above noted, areprevented.

My inventionwill be more fully understood by reference to the followingdescription taken in connection with the accom panying drawings, forminga part hereof, and in which- Fig. 1 shows the blank from which theanchor is made;

Fig. 2 shows the anchor made from the' blank shown in Fig. l;

Fig. 3 is an end view of the device shown in Fig. 2;

Figs. il and show modifications of Fig.

and-

Fig. 6 shows a modification of the blank.

By reference to the drawings it will be seen that the body portion ofthe anchor of Fig. 1 comprises a slightly curved piece of metal 1 havingintegrally attached thereto the expanding members 2. In Fig. 6 the bodyportion is rectangular but is not curved. These members may be given anydesired shape, but they are preferably inset along their intermediateportions, while the edges remain substantially in alinement with. thewalls of the body member, thus forming an anchor of general cylindricalform having portions inset so as to form a contracted throat, whichbecomes smaller toward the inner end of the device.

Formed on the body member 1 are a plurality of ribs 3, as shown in Figs.1, 2 and 3, or a series of perforations, as shown in Fig. et, or aplurality of raised points, as shown in F ig. 6. These ribs andprojections may be produced by corrugating or crimping a portion, orall, of the body member 1, as shown in Fig. 1, er by puncturing from theinside, allowing the edges 10 of the met-al A shown in Fig. 2.

\ The angular arrangement of the sides of the saw-teeth makes it easy tobring the ends of the member 1 together, because if it happens thatthese edges are not in exact register when brought together thesaw-teeth will throw 'them into register by means of this angularrelation. Once the device is put in position it remains in thatposition, and when inserted in a suitable opening for use, the ribs 3 oredges 10 of the punctures or raised points 11, come in contact with thewalls of the opening and not only prevent the device from turning when abolt is screwed into it, but prevent the expansion of the body member l.

The screwing of a suitable bolt into the anchor causes the lends 2 tobecome separated. As the screw or bolt or other expansion member isscrewed into the device, the point of maximum pressure recedes from themember 1 and since, in order to get the best results, the severalexpanding members must be held in exact relation to each other so thatthe threads ofthe expanding members 2 register properly, theuse of meansto keep the ends of the member 1 in revister is particularly desirablein a bolt anc or of this character.

Froma practical'point of view it is impossible to drill holes inconcrete and similar places which will be perfectly round and f iformation renders the members 2 extremely rigid with regardto transversemotion so that any distortion or displacement which occurs at the innerends of these members may be transmitted to the member 1. The peculiarformation referred to is that of the upturned edges of the members asshown in Fig. 2. It will be apparent that this formation renders thesemembers extremely rigid.

I have overcome these defects by providing means for keeping the ends ofthe member 1 in register with each other as above described.

One reason why the member 1 is not made from a solid piece as in theJoseph patent, thereby avoiding the possibility of displacing the endsof the member 1, is that a very decided saving in material is effectedby manufacturing the device from the blank as shown in Figs. l and wthatis, by bending the `metal upon itself into the shape shown in Fig. 2.Another reason is that when the device is made from the blanks shownherein the metal retains its original strength because it is not, duringmanufacture, subjected to the strain resulting from drawing, and thismakes a much stronger finished article.

Referring to the device in Fig. 6, it will be noted that the blank showntherein is of the general rectangular form but having a greater distancebetween the expanding members 2 adjacent the body portion l than isfound in the blank of Fig. 1.

The process of manufacturing an anchor from the blank shown in Fig. 6 isas follows:

The blank is stamped from a suitable piece of metal and the expansionmembers areVV gating of the body member 1 forms the ribs v 3 and at thesame time shortens the distance between the adjacent expanding membersthereby bringing them into proper relation with each other. The ribs inthis case as in Fig. 1 act to prevent the rotation of the device whilethe expansion bolt is being screwed into place.

The ribs 3 may be ap lied to a blank such as that shown in the 'Iosephpatent above mentioned, which blank is circular having integral radialexpansion members, thereby producing an article such as that of Fig. 2.

I wish it to be understood that the blank shown in Fig. l may be castinstead of punched, and when so `cast, being provided,

with the locking means and the ribs or other projections, this blankwhen rolled into cylindrical form is in substance the equivalent of thedevice shown in Fig. 2. This device may, of course, be made of anysuitable material such as malleable cast-iron, cast lead, brass orbronze.

It is apparent that many changes may be made in the details of thedevice shown, and such modifications are intended to be covered as fallwithin the scope of the appended claims.

Having described my invention what I claim as new and desire t0 secureby Letters Patent is:

l. A bolt anchor comprising a sheet metal body member With separateends, a plurality of expansion members integral with the body member andeach having a portion inset to form a tapering throat axially alinedwith the bore of the body portion, and tooth like projections on theends of the body member which projections intert to cause said ends toregister.

2. A bolt anchor comprising a sheet metal body member with separateends, a plurality of expansion members integral with said body memberand each having a portion inset to form a tapering throat axially alinedwith the bore of the body portion, saw teeth on the ends of the bodymember for causing said ends to register, and projections on the bodymember.

In testimony whereof, I have signed my name to this specification.

CHARLES S. GIRVAN.

